Hydraulic operating means



Feb. 28,71928. l y w. J.S`M|TH HYDRAULIC QPERATING' MEANS Filed may 2:5. 19.25

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Patented Feb. 28, 1928.

PATENT oFFlcE.

WILLIAM J'. SMITH, OF PHILADELPHIA, PENNSYLVANIA.

HYDRAULIC OPERATING MEANS.

Application tiled lay 28,

This invention relates -to means for imparting a reciprocatory movement, and it relates particularly to means for reciprocating the work table of a planer, the tool slide 5 of a Shaper, the ram of a hydraulic press, to

similarly movable parts in machine tools other than those mentioned, and to the reciprocating of arts of other structures.

A great desi eratum in machine tools of l the character referred to is to effect the return, idle or non-working movement or stroke of a part with greater speed than that of the operative movement, in order that for economic reasons an operation under way l may be rendered as nearly continuous as practicable.

The object of the present invention is to provide means for imparting a reciprocatory movement to parts of machine tools and similar devices in which the motive power, for instance, a liquid under pressure, may, through suitable instrumentalities, be governed to impart a working stroke to operative parts of such machinery and a return or idle stroke of greater speed than that` of the working stroke. A further object is to provide means for imparting a reciprocatory movement, for instance, to parts ofmachine tools by the utilization of a uid under pressure having incorporated therein mea-ns whereby the entire pressure of the iuid may automatically be directed to the accomplishment of a rapid return or non-working stroke of the reciprocated part, by concentrating the pressure on a smaller area of the actuating means than that utilized in the Working stroke.

As an illustration of the generic idea involved in the invention, one form of embodiment is herein shown and described. A deof a planar, the werk ta 1e being broken 1928. Serial No. 640,851.

away to show the disposition of the operatingvcyllnders employed.

igure 2 is a dlagrammatic sectional view, showing the general arrangement of the operating parts. Fi ure 3 'is a detail, sectional view, showlng t e spring plungers by which the valve employed2 is operated.

The driving means herein described contemplates the use of a Huid, for instance, andpreferably, oil, which is su plied to the motive parts constantly and un er a uniform pressure during the operation of the tool or other mechanism to which such parts are applied. To this end a force pump 1 of any sultable construction is connected with an e1ec tric or other motor 2 by which the pump 1s driven, and which is run constantly during such operation. The suction port of the pump is connected by a pipe 3 with an o 11 tank 4, and the discharge pipe 5 of the pump 1s connected with the inlet port 6 of a valve 7 which is secured to the frame 8 of a planer adjacent to the work table 9'of the planer.

The valve has arranged in it a sliding valve stem 10 having heads 11 and 12 movable to permit passage of oil received into the valve through the inlet port 6, through the outlet port 13 of the valve or through the outlet port 14 thereof. The chamber 15 in which the valve stem and heads are located is connected at each end, b a passage 16, with a discharge chamber 1 and this chamber is connected by a pipe 18 with the oil tank 4.

A slidable bar 19 located at the upper end of the valve is connected by rods 20 to the valve stem, and the bar has on it a projection 21, which extends at one end into the paths of movements of spring plungers 22 attached to the work table 9. The other end of the project-ion 21 extends outward from the bar and, affords a handle by which the valve may 'be operated manually. The spring plungers are secured to the work table by hangers or brackets 23 movable longitudinally of the work table, and provided with jam nuts operated by handles 24 for securing them in place.

By means of the described construction and arrangement of parts an automatic operation of the valve'takes place when, 1n

the movement of the work table, one or the other of the spring plungers contacts with the projection from the sliding bar of the valve. Thus, for instance, should the parts of the valve be in such positions that the inlet port 6 of the valve is in communication with the outlet port 13 a'forward movement of the work table would, when the rear spring plunger contacts with the projection, shift the valve to its opposite position and establish a communication between the inlet port 6 and the outlet port 14. When the parts are in the first positions referred to a communication is established between the outlet port 14, through one of the passa es 16, the discharge chamber-17, and the pipe 18 to the tank, and when the parts are in the other position referred to a like connection between the port 13 and the tank is established. From this it will be clear that as the work table reciprocates the oil is alternately projected through and discharged from the outlet ports of the valve automatically, and that the times of operating the valve, in respect of the movements of the work table, may be determined by the adjustment of the hangers by which the spring plungers are maintained. W

The reciprocation of the work table is effected by the utilization of the oil-under pressure alternately forced through and discharged from the outlet ports of the valve operating as hereinbefore described. To accomplish this a plurality of cylinders 25, 26, having pistons 27 and 28 connected by their rods 29 and 30, and the yoke 31 ywith a projection 32 extending from the lower face of the work table, are employed. In the present embodiment of the invention two cylinders are shown, the cylinder 26 being smaller in diameter than the cylinder 25. The rear end of the cylinder 26 is connected with the outlet port 13 of the valve by a pipe 33, and the rear end of the cylinder 25 is connected with the pipe 33 by a branch pipe 34. The forward end of the cylinder 26 is connected to the outlet port 14 of the valve by a pipe 35.

The forward end of the cylinder 25 is not connected with the valve, and, in order that air ma freely be drawn into and expelled from t e forward end of the cylinder during the movements of its piston, to avoid impeding the movements of the latter, such end is provided with a vent opening 36.

During the operation of the planer oil is continuously supplied, and under uniform pressure, by the pump to the valve, and by the latter is controlled in its introduction into and discharge from the cylinders. Assuming that the pistons of the valves are at the limits of their rearward movements, the valve is operated by hand to bring the valve headsf to the positions shown in the drawing. This "allows admission of oil through the outlet port 13 of the valve to the rear ends of the cylinders, causes forward movements of the pistons of the cylinders, and, by reason of the described connection, a corresponding forward working stroke of the the rear ends of the pistons and the tanky to allow the discharge from the cylinders of the oil utilized for effecting the forward movements of the parts. bimultaneously with the establishment of this connection theforward end of the cylinder 26 is connected through the valve with the pump and receives the entire discharge of the oil from the pump. The impositionv of the pressure of oil delivered from the pump upon the forward side of the piston of the cylinder 26 results in rearward movementsof the pistons of the cylinders and of the work table. This rearward, non-working movement is caused by the concentration upon the single piston of the entire pressure of oil induced by the pump, and consequently is very rapid and results in great economy of time in the use of the tool.

Preferably, as herein shown, where two operating cylinders are used, that by which the idle or return movement is caused is smaller in diameter than its fellow, in order that the arca of surface on which the oil operates during the return stroke shall, for the purpose of attaining speed of movement, be much smaller than that operated upon to cause the working stroke.

The piston rods of the cylinders being connected by the yoke 31, the piston of the cylinder 25 is carried rearward on the rearward stroke of the piston of the cylinder 26. Consequently, when on the rearward movement of the work table the forward spring plunger contacts with the projection from the sliding bar of the valve, and shifts the parts ofthe latter to cause them to assume their initialv positions, the pistons of both cylinders are in positions to receive the impact of the oil to cause a forward operative movement of the work table. The forward and rearward movements of the work table, the lengths of which may be governed in an obviousmanner by the shifting of the hangers carrying the spring plungers, and the automatic reversal of the movements, will continue until the valve is manually operated to cut oft' passage of oil from the puppA through the valve.

ile two operating cylinders are hereinbefore describedas being used for imparting a forward or working stroke to the work table, and one specified as used to cause the returnstroke, it will be clear that any end or ends of a number` of cylinders may be used for the purposes, provided a lesser number, receiving the entire pressure of oil supplied, is used to effect the return stroke than is used to cause the working stroke.

1. In a device for accomplishing the working stroke of a reciprocating member of a machine tool and a more rapid idle or return stroke, a plurality of separate cylinders having pistons which are connected to the reciprocatory member, means for supplying fluid at a constant pressure to one end of each cylinder to eiect ayworking stroke of the reciprocatory member and for directing Huid at the same pressure to the opposite less number of cylinders, having a total capacity less than that utilized in the forward stroke, to accomplish the idle or return stroke.

2. In a device for accomplishing the working stroke of a reciprocating member of a machine tool and a more rapid idle or return stroke, a plurality of separate cylinders having pistons which are connected to the reciprocating member, means for supplying fluid at a constant pressure, a valve connected to the Huid supply and to the cylinders for directing the fluid to one end of each cylinder to effect a Working stroke of the reciprocating member and for directing fluid at the same pressure to the opposite end or ends of av less number of cylinders having a total capacity less than that utilized in the forward stroke, to accomplish the idle or return stroke.

3. In a device for accomplishing the working stroke of a reciprocating member of a machine tool and a more rapid idle or return stroke, a plurality of separate cylinders having pistons which are connected to the reci rocating member, means for supplying uid at a constant pressure, a valve automatically operated during the movements of the reciprocating member connected to the fluid supply` and to the cylinders for directing the-fluid to one end of each cylinder to effect a working stroke of the reciprocating member and for directing fluid at the same pressure to the opposite end or ends of a less number of cylinders having a total capacity less than that utilized in the forward stroke, the idle or return stroke.

In testimony whereof I aiix my Signature.

WILLIAM J. SMITH.

to accomplish 

